// Sources flattened with hardhat v2.4.1 https://hardhat.org

// File @openzeppelin/contracts/token/ERC20/IERC20.sol@v4.1.0

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}


// File @openzeppelin/contracts/utils/Address.sol@v4.1.0



pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}


// File @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol@v4.1.0



pragma solidity ^0.8.0;


/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}


// File @openzeppelin/contracts/utils/Context.sol@v4.1.0



pragma solidity ^0.8.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}


// File @openzeppelin/contracts/access/Ownable.sol@v4.1.0



pragma solidity ^0.8.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}


// File @openzeppelin/contracts/security/ReentrancyGuard.sol@v4.1.0



pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor () {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}


// File contracts/Vesting.sol



pragma solidity =0.8.4;
/**
 * @title Vesting contract with batch lock and claim possibility,
 *      support only target token, user can claim and get actual
 *      reward data in range dependant on selected lock index.
 */
contract Vesting is Ownable, ReentrancyGuard {
    using SafeERC20 for IERC20;

    uint256 public constant MAX_LOCK_LENGTH = 100;

    IERC20 public immutable token;
    uint256 public immutable startAt;

    struct LockBatchInput {
        address account;
        uint256[] unlockAt;
        uint256[] amounts;
    }

    struct Lock {
        uint256[] amounts;
        uint256[] unlockAt;
        uint256 released;
    }

    struct Balance {
        Lock[] locks;
    }

    mapping (address => Balance) private _balances;

    event TokensVested(address indexed _to, uint256 _amount);
    event TokensClaimed(address indexed _beneficiary, uint256 _amount);

    constructor(IERC20 _baseToken, uint256 _startAt) {
        token = _baseToken;
        startAt = _startAt;
    }

    /**
     * @dev Returns {_participant} vesting plan by {_index}.
     */
    function getLocks(address _participant, uint _index)
        external
        view
        returns (
            uint256[] memory amounts,
            uint256[] memory unlocks
        )
    {
        Lock memory _lock = _balances[_participant].locks[_index];
        amounts = _lock.amounts;
        unlocks = _lock.unlockAt;
    }

    /**
     * @dev Returns amount of vesting plans by {_participant} address.
     */
    function getLocksLength(address _participant) external view returns (uint256) {
        return _balances[_participant].locks.length;
    }

    /**
     * @dev Returns vesting plan {_lockIndex} length by {_participant} address.
     */
    function getItemsLengthByLockIndex(address _participant, uint256 _lockIndex)
        external
        view
        returns (uint256)
    {
        require(_balances[_participant].locks.length > _lockIndex, "Index not exist");

        return _balances[_participant].locks[_lockIndex].amounts.length;
    }

    /**
     * @dev Locking {_amounts} with {_unlockAt} date for specific {_account}.
     */
    function lock(address _account, uint256[] memory _unlockAt, uint256[] memory _amounts)
        external
        onlyOwner
        returns (uint256 totalAmount)
    {
        require(_account != address(0), "Zero address");
        require(
            _unlockAt.length == _amounts.length &&
            _unlockAt.length <= MAX_LOCK_LENGTH,
            "Wrong array length"
        );
        require(_unlockAt.length != 0, "Zero array length");

        for (uint i = 0; i < _unlockAt.length; i++) {
            if (i == 0) {
                require(_unlockAt[0] >= startAt, "Early unlock");
            }

            if (i > 0) {
                if (_unlockAt[i-1] >= _unlockAt[i]) {
                    require(false, "Timeline violation");
                }
            }

            totalAmount += _amounts[i];
        }

        token.safeTransferFrom(msg.sender, address(this), totalAmount);

        _balances[_account].locks.push(Lock({
            amounts: _amounts,
            unlockAt: _unlockAt,
            released: 0
        }));

        emit TokensVested(_account, totalAmount);
    }


    /**
     * @dev Same as {Vesting.lock}, but in the batches.
     */
    function lockBatch(LockBatchInput[] memory _input)
        external
        onlyOwner
        returns (uint256 totalAmount)
    {
        uint256 inputsLen = _input.length;

        require(inputsLen != 0, "Empty input data");

        uint256 lockLen;
        uint i;
        uint ii;
        for (i; i < inputsLen; i++) {
            if (_input[i].account == address(0)) {
                require(false, "Zero address");
            }

            if (
                _input[i].amounts.length == 0 ||
                _input[i].unlockAt.length == 0
            ) {
                require(false, "Zero array length");
            }

            if (
                _input[i].unlockAt.length != _input[i].amounts.length ||
                _input[i].unlockAt.length > MAX_LOCK_LENGTH
            ) {
                require(false, "Wrong array length");
            }

            lockLen = _input[i].unlockAt.length;
            for (ii; ii < lockLen; ii++) {
                if (ii == 0) {
                    require(_input[i].unlockAt[0] >= startAt, "Early unlock");
                }

                if (ii > 0) {
                    if (_input[i].unlockAt[ii-1] >= _input[i].unlockAt[ii]) {
                        require(false, "Timeline violation");
                    }
                }

                totalAmount += _input[i].amounts[ii];
            }

            ii = 0;
        }

        token.safeTransferFrom(msg.sender, address(this), totalAmount);

        uint amount;
        uint l;

        i = 0;
        for (i; i < inputsLen; i++) {
            _balances[_input[i].account].locks.push(Lock({
                amounts: _input[i].amounts,
                unlockAt: _input[i].unlockAt,
                released: 0
            }));

            l = _input[i].amounts.length;
            ii = 0;
            if (l > 1) {
                for (ii; ii < l; ii++) {
                    amount += _input[i].amounts[ii];
                    if (ii == l - 1) {
                        emit TokensVested(_input[i].account, amount);
                        amount = 0;
                    }
                }
            } else {
                emit TokensVested(_input[i].account, _input[i].amounts[0]);
            }
        }
    }

    /**
     * @dev Returns next unlock timestamp by all locks, if return zero,
     *      no time points available.
     */
    function getNextUnlock(address _participant) external view returns (uint256 timestamp) {
        uint256 locksLen = _balances[_participant].locks.length;
        uint currentUnlock;
        uint i;
        for (i; i < locksLen; i++) {
            currentUnlock = _getNextUnlock(_participant, i);
            if (currentUnlock != 0) {
                if (timestamp == 0) {
                    timestamp = currentUnlock;
                } else {
                    if (currentUnlock < timestamp) {
                        timestamp = currentUnlock;
                    }
                }
            }
        }
    }

    /**
     * @dev Returns next unlock timestamp by {_lockIndex}.
     */
    function getNextUnlockByIndex(address _participant, uint256 _lockIndex)
        external
        view
        returns (uint256 timestamp)
    {
        uint256 locksLen = _balances[_participant].locks.length;

        require(locksLen > _lockIndex, "Index not exist");

        timestamp = _getNextUnlock(_participant, _lockIndex);
    }

    /**
     * @dev Returns total pending reward by {_participant} address.
     */
    function pendingReward(address _participant) external view returns (uint256 reward) {
        reward = _pendingReward(_participant, 0, _balances[_participant].locks.length);
    }

    /**
     * @dev Returns pending reward by {_participant} address in range.
     */
    function pendingRewardInRange(address _participant, uint256 _from, uint256 _to)
        external
        view
        returns (uint256 reward)
    {
        reward = _pendingReward(_participant, _from, _to);
    }

    /**
     * @dev Claim available reward.
     */
    function claim(address _participant) external nonReentrant returns (uint256 claimed) {
        claimed = _claim(_participant, 0, _balances[_participant].locks.length);
    }

    /**
     * @dev Claim available reward in range.
     */
    function claimInRange(address _participant, uint256 _from, uint256 _to)
        external
        nonReentrant
        returns (uint256 claimed)
    {
        claimed = _claim(_participant, _from, _to);
    }

    function _pendingReward(address _participant, uint256 _from, uint256 _to)
        internal
        view
        returns (uint256 reward)
    {
        uint amount;
        uint released;
        uint i = _from;
        uint ii;
        for (i; i < _to; i++) {
            uint len = _balances[_participant].locks[i].amounts.length;
            for (ii; ii < len; ii++) {
                if (block.timestamp >= _balances[_participant].locks[i].unlockAt[ii]) {
                    amount += _balances[_participant].locks[i].amounts[ii];
                }
            }

            released += _balances[_participant].locks[i].released;
            ii = 0;
        }

        if (amount >= released) {
            reward = amount - released;
        }
    }

    function _claim(address _participant, uint256 _from, uint256 _to)
        internal
        returns (uint256 claimed)
    {
        uint amount;
        uint released;
        uint i = _from;
        uint ii;
        for (i; i < _to; i++) {
            uint toRelease;
            uint len = _balances[_participant].locks[i].amounts.length;
            for (ii; ii < len; ii++) {
                if (block.timestamp >= _balances[_participant].locks[i].unlockAt[ii]) {
                    amount += _balances[_participant].locks[i].amounts[ii];
                    toRelease += _balances[_participant].locks[i].amounts[ii];
                }
            }

            released += _balances[_participant].locks[i].released;
            if (toRelease > 0 && _balances[_participant].locks[i].released < toRelease) {
                _balances[_participant].locks[i].released = toRelease;
            }

            ii = 0;
        }

        require(amount >= released, "Nothing to claim");

        claimed = amount - released;

        require(claimed > 0, "Zero claim");

        token.safeTransfer(_participant, claimed);
        emit TokensClaimed(_participant, claimed);
    }

    function _getNextUnlock(address _participant, uint256 _lockIndex)
        internal
        view
        returns (uint256 timestamp)
    {
        Lock memory _lock = _balances[_participant].locks[_lockIndex];
        uint256 lockLen = _lock.unlockAt.length;
        uint i;
        for (i; i < lockLen; i++) {
            if (block.timestamp < _lock.unlockAt[i]) {
                timestamp = _lock.unlockAt[i];
                return timestamp;
            }
        }
    }
}